Abstract
Gait retraining is a strategy to manage altered loading patterns and pain characteristic of knee osteoarthritis. Lower walking cadence is associated with higher knee joint loading, vertical ground reaction forces, and risk for cartilage worsening. Therefore, we determined the acute effects of increasing walking cadence on measures of lower extremity loading and knee pain in knee osteoarthritis. Twenty-five participants with knee osteoarthritis (age = 62.5 ± 7.2; 76.0 % female) walked at fixed speed on an instrumented treadmill from which baseline cadence was measured. Five, randomized experimental cadence conditions (2 %, 4 %, 6 %, 8 %, or 10 % over baseline cadence) were completed. Real-time auditory and visual feedback on cadence was provided while kinematics and ground reaction forces were sampled. Linear mixed effects models evaluated the effect of cadence on knee adduction and flexion moment peaks and impulses, impact loading metrics (vertical ground reaction force impact peak, vertical average and instantaneous loading rates), and knee pain. Increasing cadence by 2-10 % did not significantly change knee adduction moment peaks or impulse. Peak knee flexion moment increased by 3-32 % and knee flexion moment impulse reduced by 2-9 % with increases in cadence, but these results were not significant (peak knee flexion moment, p = 0.070; knee flexion moment impulse, p = 0.085). Increasing cadence significantly increased the vertical impact peak (p < 0.001), and the vertical average (p = 0.010), and instantaneous (p = 0.007) loading rates. Small increases in cadence at a fixed gait speed does not significantly change surrogate measures of knee joint loading or pain, but does increase measures of impact loading.